Photonics.comJun 2016
WASHINGTON, D.C., June 30, 2016 — A high-fidelity imaging spectrometer onboard the Carnegie Airborne Observatory has enabled the creation of forest canopy maps of leaf nitrogen, phosphorous, and mass over a large portion of the biosphere covering nearly 200 million acres of Peru.

Researchers from the Carnegie Institution for Science, using airborne imaging spectroscopy in combination with geospatial modeling, described a continuum of forest canopy nitrogen, phosphorous, and leaf mass relationships that are sensitive to the range of geophysical conditions found throughout the region.

Colored portions of this map of Peru indicate differences in tropical forest canopy chemicals that control tree growth. Each color reveals a different chemical makeup among Andean and Amazonian trees that are tightly related to the underlying geology, elevation and climate. Orange and red colors indicate relatively higher nitrogen concentrations in tree canopies, while green colors indicate higher phosphorus, and blues indicate thicker and tougher leaves. All other colors indicate the continuous nature of these trade-offs. Courtesy of Greg Asner.
One of forest ecology's fundamental undertakings has long focused on how tree growth is influenced by a host of environmental factors — ranging from soils and elevation to hydrology and climate — which create an economy of resources that trees exploit through different strategies, some of which are optimized for quick growth while others favor slow growth.

The mapped continuum of factors mediating tree growth in response to the environment could help predict how the forests will respond to climate change, informing climate models and forest management practices.

"These findings also make a clear case for taking our airborne science to Earth orbit as a satellite mission,” said researcher Greg Asner. “This is the only way to create new global-scale maps, which are needed to better understand these ecological processes and to predict the roles they will play in Earth's future.”